Yesterday figures showed Britain's big six energy firms have increased their profits by £3.3bn in three years when annual household energy bills have risen £300.

The data stems from records held by energy regulator Ofgem. Labour, in a bid to show how Prime Minister Cameron has overseen a deterioration in living standards for working families, pushed them out to the media.

Caroline Flint, the Shadow Energy Secretary who compiled the figures, accused the Prime Minister of failing to tackle “rip off energy bills”.

Angela Knight, chief executive of Energy UK, representing energy firms, attacked Labour’s “disappointing and inaccurate bashing” of companies that bring heat and light to 27 million homes and business

“If a company is to stay in business it has to make a profit. And the more a company has to invest then it has to make more profit to do so,” she said.

The wider issue here, to which I have alluded before, are the issues driving price hikes. Energy firms need to make a profit, and this is steadily growing more difficult due to green measures and EU emissions targets agreed by our governments.

British Gas, for instance, is spending £1.4bn to to insulate vulnerable customers’ homes homes under the the Energy Company Obligation (ECO)

The rising cost of improving Britain’s electricity and gas networks - and meeting renewable energy targets - are quickly being fed through to customers.

Mr Todd said senior executives at some of the ‘big six’ suppliers have been strongly hinting that more price rises are "inevitable" that it is an "indisputable fact that energy costs are rising". And by costs, they don't just mean wholesale oil and gas prices.

"It may be mere coincidence, but there are distinct advantages of introducing a price rise before the cold weather hits as the increased rates kick in as gas and electricity usage rises,” Mr Todd said.

Either way, the price hikes will come thick and fast. Yes, you can fix your energy bill - use our price comparison tool to help - and should. But bigger shocks lie in await at the end of the term.

o blight our countryside and faces huge opposition, was vaguely palatable it looks like only a short term answer. The future may lie in renewable energy, but it's no good agreeing to environmental targets that cripple household budgets in the meantime.